Notes: Difloxacin-d3 is intended for use as an internal standard for the quantification of difloxacin by GC- or LC-MS. Difloxacin is a fluoroquinolone antibiotic.{32013} It is active against isolates of anaerobic bacteria, including B. fragilis, as well as Fusobacterium and Actinomyces species with MIC values ranging from ≤0.125 to 8 µg/ml. It eliminates E. coli and B. fragilis infection in a rat intra-abdominal abscess model when administered at a dose of 40 mg/kg three times per day.{49102}